Described herein is a nose cone with a viewing window and, more specifically, a nose cone with a viewing window being associatable with a tail spout of a sand handler and a vacuum hose of a vacuum system.
Inhalable and/or respirable silica dioxide (SiO2) is a major problem facing the oil and gas (O&G) industry. Silica dioxide is a commonly occurring element found in two forms—crystalline and amorphous. Quartz and sand are common examples of crystalline silica. Silica dioxide is particularly hazardous when it is broken down, creating inhalable or respirable silica dust (very small crystalline particles and/or amorphous particles). The Center for Construction Research and Training has stated that “inhaling crystalline silica dust can lead to silicosis, bronchitis, or cancer as the dust becomes lodged in the lungs and continuously irritates them.” According to the World Health Organization (WHO), whenever people inhale airborne dust at work, they are at risk of occupational disease. Year after year, both in developed and in developing countries, overexposure to dusts causes disease, temporary and permanent disabilities and deaths. Dusts in the workplace may also contaminate or reduce the quality of products, be the cause of fire and explosion, and damage the environment.
Hydraulic fracturing (fracking) is a process used to stimulate the flow of natural gas or oil so as to increase the volume (in some cases, by many hundreds of percent) and the rate at which natural gas or oil can be recovered from reservoir formations. Hydraulic fracturing actually occurs after a well hole (wellbore) is drilled. Sometimes the drilled hole is an existing oil and gas well. Hydraulic fracturing pumps large quantities of hydraulic fracturing fluid (which may include, for example, water, proppant, and chemicals) to create or restore small fractures (paths). The proppants (also referred to as “frac sand” or “industrial sand”) fracture rock so that shale gas (natural gas in shale), tight gas (natural gas in sandstone or limestone), tight oil (crude oil in shale or sandstone), and/or coal seam gas (natural gas in coal beds) can be extracted. The proppants also hold open the newly created fractures. As the proppants are used in the fracking process, they begin to at least partially breakdown into smaller particles. Further, the proppants tend to breakdown during handling (loading, transportation, and unloading). The breakdown of the proppants results in respirable silica. Respirable silica has recently been recognized as a hazard in fracking operations, which can use between several tons to two million pounds of frac sand per well site.
To reduce the hazard of respirable silica, the common practice for controlling silica dust contamination is to create a large tent structure around a “transfer belt” (t-belt) with openings for a “dragon tail” (the top of the end of the transfer belt) of one or more “sand handlers” (e.g. sand hogs, sand kings, sand bass, and mountain movers). One or more vacuum hoses are then introduced into the tent structure, facing towards the location of the sand stream coming from the tail spout. The vacuum hose has to be laid correctly or problems may ensue. If the vacuum hose is placed too close to the frac sand, the hose can end up sucking up sand. If the vacuum hose is placed too far away from the frac sand, the hose does not effectively remove the silica dust.
Another problem is that the tent structure can block the operator's sightlines. Even if an opening is made in the tent structure so that the operator can see what is going on inside the tent structure, the interior of the tent structure can be dark making it difficult to see. If the tent structure is preventing the operators from seeing what they're doing, it is difficult for the operators to make adjustments to the rate of sand transfer which is critical to the fracturing process. Adding a window to the tent structure to regain sightlines is impractical for a number of reasons. An open window will necessarily allow dust to escape because the overall volume of air within the tent is too large for the vacuum hoses to maintain sufficient negative pressure. Adding a pane of transparent material to the window to contain the dust fails as the window becomes too dirty to see through. This design often requires that a plurality of vacuum hoses be run along the ground to reach the appropriate spots, which presents a tripping hazard. Also, if a vacuum hose is not well fixed to its final location, it may shift out of place. If the tent material is loose, it may be accidentally sucked into the vacuum hose.
Tent structures can be large and cumbersome. The full tent structure requires a large setup and tear-down procedure for every job. It is not road worthy, and therefore cannot be left on the equipment. The tent structures are not particularly good at adjusting to changes in the height or position of the tail. Further, the tent structure may not contain the silica dust at the opening of the tail (e.g. the tail spout), especially when the tail is lifted higher than the top of the tent structure (which occasionally happens). By creating a large volume space with very high concentrations of silica dust, a health hazard is created if a worker must enter the area to deal with a problem.
U.S. Patent Publication No. 2012/0247335 to Stutzman et al. concerns a method of reducing silicosis caused by the inhalation of silica-containing proppant, such as silica sand and resin-coated sand, and an apparatus therefor.
U.S. Pat. No. 8,881,749 to Smith discusses a system and method for controlling silica dust during hydraulic fracturing operations. The Smith system includes a system of conduits having a plurality of inlets for collecting silica dust generated at selected points along a conveyor system. An air system pneumatically coupled to the system of conduits generates a negative pressure at each of the inlets to induce the collection of silica dust at the selected points along the conveyor.